Holy water is blessed on the Feast of the Epiphany (January 6) and any time thereafter that holy water is needed. First, the salt to be added to the water is exorcized and blessed. Then the water itself is blessed with these words:
I exorcise thee in the name of God the Father almighty, and in the name of Jesus Christ His Son, our Lord, and in the power of the Holy Ghost, that you may be able to put to flight all the power of the enemy, and be able to root out and supplant that enemy and his apostate angels; through the power of our Lord Jesus Christ, who will come to judge the living and the dead and the world by fire.
God, Who for the salvation of the human race has built your greatest mysteries upon this substance, in your kindness hear our prayers and pour down the power of your blessing into this element, prepared by many purifications. May this your creation be a vessel of divine grace to dispel demons and sicknesses, so that everything that it is sprinkled on in the homes and buildings of the faithful will be rid of all unclean and harmful things. Let no pestilent spirit, no corrupting atmosphere, remain in those places: may all the schemes of the hidden enemy be dispelled. Let whatever might trouble the safety and peace of those who live here be put to flight by this water, so that health, gotten by calling Your Holy Name, may be made secure against all attacks. Through Our Lord Jesus Christ, Thy Son, Who liveth and reigneth with Thee in the unity of the Holy Ghost, God, world without end. Amen.
How to use it
You can keep it in decorative bottles 1 for storage at home or in little flasks, made for this purpose, to carry with you. Most Catholics keep at least some in holy water fonts.
Holy water fonts for the home come in all sizes and shapes, some tacky and plastic, others quite lovely and made of alabaster, marble, porcelain, sandstone, or metals -- as inexpensive or as expensive as you like -- some resting on tables, most hanging on walls (one example is shown at right). You can buy one from most Catholic gift shops or make your own (consider using bivalve seashells as basins, or the shell motif in design. The seashell is a very ancient symbol of Baptism, and the shells of large molluscs -- weighing up to 500 pounds -- have been used in churches as basins for holy water). Tip: putting a thin sponge inside the font is said to make the water evaporate less quickly.
Catholics often keep a font near their front door, in their bedrooms' doorways, and near the family altar. Use the water in the same way you do at church, dipping your fingers into it and making the Sign of the Cross. Bless your children with it as you tuck them in at night, using your thumb to sign them with a cross of holy water on their foreheads.
Most Catholics pray "In the Name of the Father, and of the Son, and of the Holy Ghost" when blessing themselves with Holy Water, but this is another beautiful prayer:
By Thy Precious Blood and by this Holy Water, cleanse me (him/her) from my (his/her) sins, O Lord.
Another use of holy water is to give tiny sips to the sick or spiritually oppressed. It shouldn't be consumed as a beverage, mind you, but the ingestion of small amounts, or adding a few drops to foods, is common.